We propose to show feasibility of developing a wearable device to monitor human postural sway by attaching lightweight movement sensor packages directly to subjects. The wearable sensor package will contain one 2-axis microchip linear accelerometer and 2 single-axis rotational velocity sensors connected by cable to control circuitry in a belt pack. The device will provide independent data on tilt angle, linear acceleration, and rotational velocities about roll and pitch axes simultaneously. The microcontroller will control data acquisition, preprocessing and uploading of data to a notebook computer. Ten normal subjects will be tested with the device while performing a protocol that is commonly used for balance assessment. Subjects wearing the proposed device will be simultaneously monitored for center-of-force sway variations with a commonly used protocol on a computerized dynamic posturography system (CDP). Quantitative results from the sensor package will be compared with the CDP sway measurements. Windows-based software running on a notebook computer will be written to provide a menu-driven graphical user interface to the device. Our future goal is to produce an easy-to-use commercial product that provides quantitative information for assessing postural sway. This product is expected to provide new, accurate information for balance assessment and training useful for vestibular-deficient patients and falls-prevention in the elderly. PROPOSED COMMERCIAL APPLICATION: The research will provide a low cost method to monitor postural sway with microchip sensors and digital signal processing. This will have wide commercial appeal for clinicians interested in identifying patients at risk for falls, and comparing patterns of postural sway in the diagnosis and treatment of balance disorders.